view src/video/SDL_yuv.c @ 1643:51038e80ae59

More general fix for bug #189 The clipping is done at a higher level, and the low level functions are passed clipped rectangles. Drivers which don't support source clipping have not been changed, so the image will be squished instead of clipped, but at least they will no longer crash when the destination rect was out of bounds.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 17 Apr 2006 06:47:23 +0000
parents d910939febfa
children 782fd950bd46 9a7c62bbc8b3
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* This is the implementation of the YUV video surface support */

#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_yuvfuncs.h"
#include "SDL_yuv_sw_c.h"


SDL_Overlay *SDL_CreateYUVOverlay(int w, int h, Uint32 format,
                                  SDL_Surface *display)
{
	SDL_VideoDevice *video = current_video;
	SDL_VideoDevice *this  = current_video;
	const char *yuv_hwaccel;
	SDL_Overlay *overlay;

	if ( (display->flags & SDL_OPENGL) == SDL_OPENGL ) {
		SDL_SetError("YUV overlays are not supported in OpenGL mode");
		return NULL;
	}

	/* Display directly on video surface, if possible */
	if ( SDL_getenv("SDL_VIDEO_YUV_DIRECT") ) {
		if ( (display == SDL_PublicSurface) &&
		     ((SDL_VideoSurface->format->BytesPerPixel == 2) ||
		      (SDL_VideoSurface->format->BytesPerPixel == 4)) ) {
			display = SDL_VideoSurface;
		}
	}
	overlay = NULL;
        yuv_hwaccel = SDL_getenv("SDL_VIDEO_YUV_HWACCEL");
	if ( ((display == SDL_VideoSurface) && video->CreateYUVOverlay) &&
	     (!yuv_hwaccel || (SDL_atoi(yuv_hwaccel) > 0)) ) {
		overlay = video->CreateYUVOverlay(this, w, h, format, display);
	}
	/* If hardware YUV overlay failed ... */
	if ( overlay == NULL ) {
		overlay = SDL_CreateYUV_SW(this, w, h, format, display);
	}
	return overlay;
}

int SDL_LockYUVOverlay(SDL_Overlay *overlay)
{
	return overlay->hwfuncs->Lock(current_video, overlay);
}

void SDL_UnlockYUVOverlay(SDL_Overlay *overlay)
{
	overlay->hwfuncs->Unlock(current_video, overlay);
}

int SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect)
{
	SDL_Rect src, dst;
	int srcx, srcy, srcw, srch;
	int dstx, dsty, dstw, dsth;

	/* Clip the rectangle to the screen area */
	srcx = 0;
	srcy = 0;
	srcw = overlay->w;
	srch = overlay->h;
	dstx = dstrect->x;
	dsty = dstrect->y;
	dstw = dstrect->w;
	dsth = dstrect->h;
	if ( dstx < 0 ) {
		srcw += (dstx * overlay->w) / dstrect->w;
		dstw += dstx;
		srcx -= (dstx * overlay->w) / dstrect->w;
		dstx = 0;
	}
	if ( (dstx+dstw) > current_video->screen->w ) {
		int extra = (dstx+dstw - current_video->screen->w);
		srcw -= (extra * overlay->w) / dstrect->w;
		dstw -= extra;
	}
	if ( dsty < 0 ) {
		srch += (dsty * overlay->h) / dstrect->h;
		dsth += dsty;
		srcy -= (dsty * overlay->h) / dstrect->h;
		dsty = 0;
	}
	if ( (dsty+dsth) > current_video->screen->h ) {
		int extra = (dsty+dsth - current_video->screen->h);
		srch -= (extra * overlay->h) / dstrect->h;
		dsth -= extra;
	}
	if ( srcw <= 0 || srch <= 0 ||
	     srch <= 0 || dsth <= 0 ) {
		return 0;
	}
	/* Ugh, I can't wait for SDL_Rect to be int values */
	src.x = srcx;
	src.y = srcy;
	src.w = srcw;
	src.h = srch;
	dst.x = dstx;
	dst.y = dsty;
	dst.w = dstw;
	dst.h = dsth;
	return overlay->hwfuncs->Display(current_video, overlay, &src, &dst);
}

void SDL_FreeYUVOverlay(SDL_Overlay *overlay)
{
	if ( overlay ) {
		if ( overlay->hwfuncs ) {
			overlay->hwfuncs->FreeHW(current_video, overlay);
		}
		SDL_free(overlay);
	}
}